Faulty SLD Solenoid (Differential Lock Solenoid)
SLD Solenoid harness is open or shorted
SLD Solenoid circuit poor electrical connection
Faulty Engine Control Module (ECM)
Engine Light ON (or Service Engine Soon Warning Light)
The Differential Lock Solenoid or SLD Solenoid controls hydraulic pressure applied to the center differential clutch and maintains a limited-slip differential level. The Engine Control Module (ECM) determines optimum operating pressure according to signals from the throttle position sensor, and front and rear speed sensors, and controls the volume of current flow to the SLD solenoid. The Diagnostic Trouble Code (DTC) is set when the SLD solenoid output signal is on for 3.3 milliseconds or more with a duty ratio of at least 5 percent.